This proposed study involves four clinical research studies to evaluate patients with severe upper gastrointestinal bleeding (UGIB) from peptic ulcers, Mallory Weiss tears or Dieulafoy's lesions. Studies I-III are randomized controlled trials of endoscopic treatments for bleeding lesions. The purpose of this study is to find out whether combinations of epinephrine injection and thermal endoscopic coagulation can improve the rate of primary hemostasis or early rebleeding from lesion without increasing the complication rates or cost of adjustments.